The present disclosure relates to an inspection system, an inspection device, and an inspection method, for example relates to an inspection system, an inspection device, and an inspection method for inspecting a device to be inspected including an arithmetic operation unit.
A watch dog timer (WDT) is known as a mechanism for determining whether a function of a CPU (Central Processing Unit) or the like provided in a device is normal or not. In general, the watch dog timer periodically receives pulse signals from a CPU. When the watch dog timer cannot receive the pulse signals from the CPU after a predetermined time has elapsed, it determines that the CPU does not work properly and carries out a reset of the CPU or the like.
However, the above watch dog time determines that the CPU is normal when the pulse signals are input from the CPU at a constant timing. Therefore, although a timer function of the CPU can be checked, an arithmetic operation function of the CPU cannot be checked. Regarding the above problem, Japanese unexamined patent publication No. 2007-293524 discloses an inspection method for inspecting an arithmetic function of a CPU in an electronic device having a plurality of CPUs. In the electronic device disclosed in Japanese unexamined paten publication No. 2007-293524, a CPU to be inspected carries out an arithmetic operation of an arithmetic problem and sends a result of the arithmetic operation to a CPU carrying out an inspection. The CPU carrying out the inspection determines whether an arithmetic operation function of the CPU to be inspected is normal or not based on the result of the arithmetic operation received.